1. Field of the Invention
The instant invention relates generally to heating mats and more specifically it relates to an electric snow tarpaulin.
2. Description of the Prior Art
Numerous heating mats have been provided in prior art. For example, U.S. Pat. Nos. 3,806,702 to Spencer; 3,808,403 to Kanaya et al.; 4,967,057 to Bayless et al. and 5,003,157 to Hargrove all are illustrative of such prior art. While these units may be suitable for the particular purpose to which they address, they would not be as suitable for the purposes of the present invention as heretofore described.
U.S. Pat. No. 3,806,702 to Spencer shows a weatherproof electrically insulative mat has an electrical heat producing conductor therein and is adapted for placement on an exterior surface to prevent accumulation of snow on such surface. A control system for supplying current to the conductor includes a precipitation sensor, a temperature sensor and a control unit responsive to the sensors. Power is supplied to the conductor in the mat only when there is precipitation and the temperature is below thirty five degrees Fahrenheit. An improved mat structure is approximately symmetrical of the central plane thereof, so that when one side of the mat wears the mat can be reversed.
U.S. Pat. No. 3,808,403 Yoshinosuke et al. shows a heating unit sheet composed of an electroconductive high molecular material and has a high degree of safety and excellent flexibility. It is useful in many various applications, equipped with electrodes and coated with insulating materials.
U.S. Pat. No. 4,967,057 to Bayless et al. shows individual electrically heated mats, self-regulated by use of an electrical element whose resistance varies proportionately with its temperature are used for covering walking areas, to prevent accumulation of snow and ice. Each mat is provided with male and female electrical connections on the ends of short power cords, to permit any number of mats to be chained together in electrical parallel and to be used to cover, for example, a flight of stairs by positioning one mat on each stair.
U.S. Pat. No. 5,003,157 to Hargrove shows an apparatus utilizing a flexible web construction, includes a series of electrical heating resistance elements directed therethrough. The mat contains a ribbed upper surface overlying a ribbed bottom surface. The upper surface has sloping side walls positioned medially about a central ridge to direct fluid downwardly from an upper surface of the mat. Hollow chambers are optionally formed throughout the mat longitudinally thereof, overlying the electric coils to cushion the coils and simultaneously produce heat chambers for maintaining a constant temperature throughout the web construction. Further, fiber optic cables may be placed in side chambers longitudinally coextensive with side edges of the web, to illuminate boundary portions of the web for individuals during limited light conditions.